Simplicity, Simplism, Oversimplification, Sophistication, Complexity
Simplicity vs. Simplism vs. Oversimplification
Simplicity before understanding is simplistic; simplicity after understanding is simple, and a process to make it simple (simplify) is simplification.
Simplistic often means jumping from an observed phenomenon to a direct and simple explanation, missing out all the true complexity of the situation. Simplism is the tendency to oversimplify an issue or a problem by ignoring complexities or complications.
Thus, oversimplification is you have simplified the matter too much and have left out important aspects of it. The oversimplification is not wrong, but it is inadequate because it is incomplete.
Sophistication vs. Complexity
Chess is not a very sophisticated game. This is because chess achieves difficulty through complexity. There are many pieces and different moves. It is not hard to get difficulty through complexity. Sophistication depends on getting difficulty through simplicity. The L-game, for instance, invented by Edward de Bono, in which each player has only one playing piece.
from Simplicity by Edward de Bono